Genome-wide association studies have identified susceptibility loci for esophageal squamous cell carcinoma (ESCC). We conducted a meta-analysis of all single-nucleotide polymorphisms (SNPs) that showed nominally significant P-values in two previously published genome-wide scans that included a total of 2961 ESCC cases and 3400 controls. The meta-analysis revealed five SNPs at 2q33 with P< 5 × 10−8, and the strongest signal was rs13016963, with a combined odds ratio (95% confidence interval) of 1.29 (1.19–1.40) and P= 7.63 × 10−10. An imputation analysis of 4304 SNPs at 2q33 suggested a single association signal, and the strongest imputed SNP associations were similar to those from the genotyped SNPs. We conducted an ancestral recombination graph analysis with 53 SNPs to identify one or more haplotypes that harbor the variants directly responsible for the detected association signal. This showed that the five SNPs exist in a single haplotype along with 45 imputed SNPs in strong linkage disequilibrium, and the strongest candidate was rs10201587, one of the genotyped SNPs. Our meta-analysis found genome-wide significant SNPs at 2q33 that map to the CASP8/ALS2CR12/TRAK2 gene region. Variants in CASP8 have been extensively studied across a spectrum of cancers with mixed results. The locus we identified appears to be distinct from the widely studied rs3834129 and rs1045485 SNPs in CASP8. Future studies of esophageal and other cancers should focus on comprehensive sequencing of this 2q33 locus and functional analysis of rs13016963 and rs10201587 and other strongly correlated variants.
Cassava is a major tropical food crop in the Euphorbiaceae family that has high carbohydrate production potential and adaptability to diverse environments. Here we present the draft genome sequences of a wild ancestor and a domesticated variety of cassava and comparative analyses with a partial inbred line. We identify 1,584 and 1,678 gene models specific to the wild and domesticated varieties, respectively, and discover high heterozygosity and millions of single-nucleotide variations. Our analyses reveal that genes involved in photosynthesis, starch accumulation and abiotic stresses have been positively selected, whereas those involved in cell wall biosynthesis and secondary metabolism, including cyanogenic glucoside formation, have been negatively selected in the cultivated varieties, reflecting the result of natural selection and domestication. Differences in microRNA genes and retrotransposon regulation could partly explain an increased carbon flux towards starch accumulation and reduced cyanogenic glucoside accumulation in domesticated cassava. These results may contribute to genetic improvement of cassava through better understanding of its biology.
Cassava is a major source of food in tropical and subtropical regions. Here the authors sequence the genomes of wild and domesticated cassava varieties and identify genes that have been selected for and against during the evolution and domestication of this economically important crop.
The primary objective of this study investigated the role of microRNA-320 (miR-320) on left ventricular remodeling in the rat model of myocardial ischemia-reperfusion (I/R) injury, and we intended to explore the myocardial mechanism of miR-320-mediated myocardium protection. We collected 120 male Wistar rats (240–280 g) in this study and then randomly divided them into three groups: (1) sham surgery group (sham group: n = 40); (2) ischemia-reperfusion model group (I/R group: n = 40); and (3) I/R model with antagomir-320 group (I/R + antagomir-320 group: n = 40). Value changes of heart function in transesophageal echocardiography were recorded at various time points (day 1, day 3, day 7, day 15 and day 30) after surgery in each group. Myocardial sections were stained with hematoxylin and eosin (H&E) and examined with optical microscope. The degree of myocardial fibrosis was assessed by Sirius Red staining. Terminal dUTP nick end-labeling (TUNEL) and qRT-PCR methods were used to measure the apoptosis rate and to determine the miR-320 expression levels in myocardial tissues. Transesophageal echocardiography showed that the values of left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS), left ventricular systolic pressure (LVSP) and ±dp/dtmax in the I/R group were obviously lower than those in the sham group, while the left ventricular end-diastolic pressure (LVEDP) value was higher than that in the sham group. The values of LVEF, LVFS, LVSP and ±dp/dtmax showed a gradual decrease in the I/R group, while the LVEDP value showed an up tendency along with the extension of reperfusion time. The H&E staining revealed that rat myocardial tissue in the I/R group presented extensive myocardial damage; for the I/R + antagomir-320 group, however, the degree of damage in myocardial cells was obviously better than that of the I/R group. The Sirius Red staining results showed that the degree of myocardial fibrosis in the I/R group was more severe along with the extension of the time of reperfusion. For the I/R + antagomir-320 group, the degree of myocardial fibrosis was less severe than that in the I/R group. Tissues samples in both the sham and I/R + antagomir-320 groups showed a lower apoptosis rate compared to I/R group. The qRT-PCR results indicated that miR-320 expression in the I/R group was significantly higher than that in both the sham and I/R + antagomir-320 groups. The expression level of miR-320 is significantly up-regulated in the rat model of myocardial I/R injury, and it may be implicated in the prevention of myocardial I/R injury-triggered left ventricular remodeling.
microRNA-320; myocardial ischemia-reperfusion injury; left ventricular remodeling
We report improved whole-genome shotgun sequences for the genomes of indica and japonica rice, both with multimegabase contiguity, or almost 1,000-fold improvement over the drafts of 2002. Tested against a nonredundant collection of 19,079 full-length cDNAs, 97.7% of the genes are aligned, without fragmentation, to the mapped super-scaffolds of one or the other genome. We introduce a gene identification procedure for plants that does not rely on similarity to known genes to remove erroneous predictions resulting from transposable elements. Using the available EST data to adjust for residual errors in the predictions, the estimated gene count is at least 38,000–40,000. Only 2%–3% of the genes are unique to any one subspecies, comparable to the amount of sequence that might still be missing. Despite this lack of variation in gene content, there is enormous variation in the intergenic regions. At least a quarter of the two sequences could not be aligned, and where they could be aligned, single nucleotide polymorphism (SNP) rates varied from as little as 3.0 SNP/kb in the coding regions to 27.6 SNP/kb in the transposable elements. A more inclusive new approach for analyzing duplication history is introduced here. It reveals an ancient whole-genome duplication, a recent segmental duplication on Chromosomes 11 and 12, and massive ongoing individual gene duplications. We find 18 distinct pairs of duplicated segments that cover 65.7% of the genome; 17 of these pairs date back to a common time before the divergence of the grasses. More important, ongoing individual gene duplications provide a never-ending source of raw material for gene genesis and are major contributors to the differences between members of the grass family.
Comparative genome sequencing of indica and japonica rice reveals that duplication of genes and genomic regions has played a major part in the evolution of grass genomes
Long-term noninvasive cell tracing by fluorescent probes is of great importance to life science and biomedical engineering. For example, understanding genesis, development, invasion and metastasis of cancerous cells and monitoring tissue regeneration after stem cell transplantation require continual tracing of the biological processes by cytocompatible fluorescent probes over a long period of time. In this work, we successfully developed organic far-red/near-infrared dots with aggregation-induced emission (AIE dots) and demonstrated their utilities as long-term cell trackers. The high emission efficiency, large absorptivity, excellent biocompatibility, and strong photobleaching resistance of the AIE dots functionalized by cell penetrating peptides derived from transactivator of transcription proteins ensured outstanding long-term noninvasive in vitro and in vivo cell tracing. The organic AIE dots outperform their counterparts of inorganic quantum dots, opening a new avenue in the development of fluorescent probes for following biological processes such as carcinogenesis.
Plasmablastic lymphoma (PBL) is an aggressive neoplasm exclusively occurring in AIDS patients. Recently, increasing cases of human immunodeficiency virus (HIV)-negative PBL have been reported. No standard therapy protocol is currently available since there is a great difference between PBL with and without HIV infection. Here, we present a rather rare case of HIV-negative PBL in the neck that dramatically responded to radiotherapy alone. Our case highlights the possibility of PBL in the neck and helps to expand our understanding of this separate lymphoma. The related literature review summarized the clinicopathological features and treatment status of HIV-negative PBL.
HIV-negative; Plasmablastic lymphoma; Radiotherapy
Solitary Fibrous Tumor of the Pleura (SFTP) is an uncommon neoplasm which grows slowly. For some cases, surgery is warranted. However, for unresectable ones, the standard strategy has not been established yet. We presented a rare case of recurrent malignant intrathoracic solitary fibrous tumor. It was impossible to resect the tumor. Radiotherapy alone achieved a significant improvement effect.
Radiotherapy; recurrent; solitary fibrous tumor of the pleura
AIM: To investigate the effects of dihydromyricetin (DHM) on the migration and invasion of human hepatic cancer cells.
METHODS: The hepatoma cell lines SK-Hep-1 and MHCC97L were used in this study. The cells were cultured in RPIM-1640 medium supplemented with 10% fetal bovine serum at 37 °C in a humidified 5% CO2 incubator. DHM was dissolved in dimethyl sulfoxide and diluted to various concentrations in medium before applying to cells. MTT assays were performed to measure the viability of the cells after DHM treatment. Wound healing and Boyden transwell assays were used to assess cancer cell motility. The invasive capacity of cancer cells was measured using Matrigel-coated transwell chambers. Matrix metalloproteinase (MMP)-2/9 activity was examined by fluorescence analysis. Western blot was carried out to analyze the expression of MMP-2, MMP-9, p-38, JNK, ERK1/2 and PKC-δ proteins. All data were analyzed by Student’s t tests in GraphPad prism 5.0 software and are presented as mean ± SD.
RESULTS: DHM was found to strongly inhibit the migration of the hepatoma cell lines SK-Hep-1 (without DHM, 24 h: 120 ± 8 μmol/L vs 100 μmol/L DHM, 24 h: 65 ± 10 μmol/L, P < 0.001) and MHCC97L (without DHM, 24 h: 126 ± 7 μmol/L vs 100 μmol/L DHM, 24 h: 74 ± 6 μmol/L, P < 0.001). The invasive capacity of the cells was reduced by DHM treatment (SK-Hep-1 cells without DHM, 24 h: 67 ± 4 μmol/L vs 100 μmol/L DHM, 24 h: 9 ± 3 μmol/L, P < 0.001; MHCC97L cells without DHM, 24 h: 117 ± 8 μmol/L vs 100 μmol/L DHM, 24 h: 45 ± 2 μmol/L, P < 0.001). MMP2/9 activity was also inhibited by DHM exposure (SK-Hep-1 cells without DHM, 24 h: 600 ± 26 μmol/L vs 100 μmol/L DHM, 24 h: 100 ± 6 μmol/L, P < 0.001; MHCC97L cells without DHM, 24 h: 504 ± 32 μmol/L vs 100 μmol/L DHM 24 h: 156 ± 10 μmol/L, P < 0.001). Western blot analysis showed that DHM decreased the expression level of MMP-9 but had little effect on MMP-2. Further investigation indicated that DHM markedly reduced the phosphorylation levels of p38, ERK1/2 and JNK in a concentration-dependent manner but had no impact on the total protein levels. In addition, PKC-δ protein, a key protein in the regulation of MMP family protein expression, was up-regulated with DHM treatment.
CONCLUSION: These findings demonstrate that DHM inhibits the migration and invasion of hepatoma cells and may serve as a potential candidate agent for the prevention of HCC metastasis.
Dihydromyricetin; Migration; Invasion; Hepatic cancer; Matrix metalloproteinase-9
Identification of protein binding sites is critical for studying the function of the proteins. In this paper, we proposed a method for protein binding site prediction, which combined the order profile propensities and hidden Markov support vector machine (HM-SVM). This method employed the sequential labeling technique to the field of protein binding site prediction. The input features of HM-SVM include the profile-based propensities, the Position-Specific Score Matrix (PSSM), and Accessible Surface Area (ASA). When tested on different data sets, the proposed method showed promising results, and outperformed some closely relative methods by more than 10% in terms of AUC.
We find that CsGAMYB1, a positive regulator of GA signalling, can regulate sex expression of cucumber. This provides a new insight into the mechanism of GA in sex determination.
Cucumber (Cucumis sativus L.) is a typical monoecious vegetable with individual male and female flowers, and has been used as a model plant for sex determination. It is well known that sex differentiation of cucumber can be regulated by phytohormones, such as gibberellic acid (GA) and ethylene. The molecular mechanism of female sex expression modulated by ethylene has been widely understood, but how GA controls male sex expression remains elusive. In hermaphroditic Arabidopsis and rice, GA can regulate stamen and anther development via the transcriptional regulation of GAMYB. Here we characterized a GAMYB homologue CsGAMYB1 in cucumber. We found that CsGAMYB1 is predominantly expressed in male flower buds, where its expression is upregulated by GA3 treatment. CsGAMYB1 protein is localized in the nucleus. CsGAMYB1 can partially rescue stamen development and fertility phenotypes of an Arabidopsis myb33 myb65 double mutant. However, constitutive overexpression of CsGAMYB1 in wild-type Arabidopsis resulted in male sterility, which mimics the effect of GA overdose in flower development. Knockdown of CsGAMYB1 in cucumber decreases the ratio of nodes with male and female flowers, and ethylene is not involved in this process. Our data suggest that CsGAMYB1 regulates sex expression of cucumber via an ethylene-independent pathway.
CsGAMYB1; cucumber; ethylene; GAMYB; gibberellin; sex expression.
Transcription activator-like effector nucleases (TALENs) are a powerful new approach for targeted gene disruption in various animal models, but little is known about their activities in Mus musculus, the widely used mammalian model organism. Here, we report that direct injection of in vitro transcribed messenger RNA of TALEN pairs into mouse zygotes induced somatic mutations, which were stably passed to the next generation through germ-line transmission. With one TALEN pair constructed for each of 10 target genes, mutant F0 mice for each gene were obtained with the mutation rate ranged from 13 to 67% and an average of ∼40% of total healthy newborns with no significant differences between C57BL/6 and FVB/N genetic background. One TALEN pair with single mismatch to their intended target sequence in each side failed to yield any mutation. Furthermore, highly efficient germ-line transmission was obtained, as all the F0 founders tested transmitted the mutations to F1 mice. In addition, we also observed that one bi-allele mutant founder of Lepr gene, encoding Leptin receptor, had similar diabetic phenotype as db/db mouse. Together, our results suggest that TALENs are an effective genetic tool for rapid gene disruption with high efficiency and heritability in mouse with distinct genetic background.
Cryptochromes are blue light receptors that mediate light regulation of gene expression in all major evolution lineages, but the molecular mechanism underlying cryptochrome signal transduction remains not fully understood [1, 2]. It has been reported that cryptochromes suppress activity of the multifunctional E3 ubiquitin ligase CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) to regulate gene expression in response to blue light [3, 4]. But how plant cryptochromes mediate light suppression of COP1 activity remains unclear. We report here that Arabidopsis CRY2 (cryptochrome 2) undergoes blue light-dependent interaction with the COP1-interacting protein SUPPRESSOR OF PHYTOCHROME A 1 (SPA1) [5, 6]. We demonstrate that SPA1 acts genetically downstream from CRY2 to mediate blue light suppression of the COP1-dependent proteolysis of the flowering-time regulator CONSTANS (CO) [7, 8]. We further show that blue light-dependent CRY2-SPA1 interaction stimulates CRY2-COP1 interaction. These results reveal for the first time a wavelength-specific mechanism by which a cryptochrome photoreceptor mediates light regulation of protein degradation to modulate developmental timing in Arabidopsis.
Genetic factors are thought to play a role in development for colorectal carcinogenesis. ICAM-1 is a polymorphic gene, thus, the present study investigated the relationship between the polymorphisms of ICAM-1 and the susceptibility and phenotypical characteristics of colorectal cancer (CRC).
The polymorphisms at ICAM-1 exon 4 (G241R) and exon 6 (E469K) were detected by PCR with sequence-specific primers. The relationship between specific genotypes of ICAM-1 and differentiation of CRC was evaluated by the histological grade.
We showed only GG genotype of ICAM-1 individuals in either CRC or normal controls. The KK genotype of ICAM-1 K469E was found more frequently than in the controls (P < 0.05). Patients with well-differentiated CRC displayed the KK more frequently than those of poor differentiation (P < 0.05).
The findings indicate that polymorphisms of G241R are rare in Chinese population and that KK genotype of ICAM-1 K469E is significantly associated with well differentiation of CRC.
Escherichia coli strains causing postweaning diarrhea (PWD) and edema disease (ED) in pigs are limited to a number of serogroups, with O8, O45, O138, O139, O141, O147, O149, and O157 being the most commonly reported worldwide. In this study, a DNA microarray based on the O-antigen-specific genes of all 8 E. coli serogroups, as well as 11 genes encoding adhesion factors and exotoxins associated with PWD and ED, was developed for the identification of related serogroups and virulence gene patterns. The microarray method was tested against 186 E. coli and Shigella O-serogroup reference strains, 13 E. coli reference strains for virulence markers, 43 E. coli clinical isolates, and 12 strains of other bacterial species and shown to be highly specific with reproducible results. The detection sensitivity was 0.1 ng of genomic DNA or 103 CFU per 0.3 g of porcine feces in mock samples. Seventeen porcine feces samples from local hoggeries were examined using the microarray, and the result for one sample was verified by the conventional serotyping methods. This microarray can be readily used to screen for the presence of PWD- and ED-associated E. coli in porcine feces samples.
AIM: To investigate the value of computed tomography (CT) spectral imaging in the evaluation of intestinal hemorrhage.
METHODS: Seven blood flow rates were simulated in vitro. Energy spectral CT and mixed-energy CT scans were performed for each rate (0.5, 0.4, 0.3, 0.2, 0.1, 0.05 and 0.025 mL/min). The detection rates and the contrast-to-noise ratios (CNRs) of the contrast agent extravasation regions were compared between the two scanning methods in the arterial phase (AP) and the portal venous phase (PVP). Comparisons of the CNR values between the PVP and the AP were made for each energy level and carried out using a completely random t test. A χ2 test was used to compare the detection rates obtained from the two scanning methods.
RESULTS: The total detection rates for energy spectral CT and mixed-energy CT in the AP were 88.57% (31/35) and 65.71% (23/35), respectively, and the difference was significant (χ2 = 5.185, P = 0.023); the total detection rates in the PVP were 100.00% (35/35) and 91.4% (32/35), respectively, and the difference was not significant (χ2 = 1.393, P = 0.238). In the AP, the CNR of the contrast agent extravasation regions was 3.58 ± 2.09 on the mixed-energy CT images, but the CNRs were 8.78 ± 7.21 and 8.83 ± 6.75 at 50 and 60 keV, respectively, on the single-energy CT images, which were significantly different (3.58 ± 2.09 vs 8.78 ± 7.21, P = 0.031; 3.58 ± 2.09 vs 8.83 ± 6.75, P = 0.029). In the PVP, the differences between the CNRs at 40, 50 and 60 keV different monochromatic energy levels and the polychromatic energy images were significant (19.35 ± 10.89 vs 11.68 ± 6.38, P = 0.010; 20.82 ± 11.26 vs 11.68 ± 6.38, P = 0.001; 20.63 ± 10.07 vs 11.68 ± 6.38, P = 0.001). The CNRs at the different energy levels in the AP and the PVP were significantly different (t = -2.415, -2.380, -2.575, -2.762, -2.945, -3.157, -3.996 and -3.189).
CONCLUSION: Monochromatic energy imaging spectral CT is superior to polychromatic energy images for the detection of intestinal hemorrhage, and the detection was easier in the PVP compared with the AP.
Spectral imaging; Computed tomography; Monochromatic energy imaging; Small bowel bleeding
RNA interference (RNAi) has been successfully used as a promising method to inhibit the replication of different viruses, including human immunodeficiency virus (HIV). Gene mutation is a hurdle for the anti-HIV by RNAi. Although prone to mutation, some genes are conserved and limited in functionally important regions. The gag gene is conserved in different subtypes and plays an important role in the assembly of HIV viral particle. Here, we identified subtypes and conserved sequences within forty-four gag genes from the epidemic strains among men who have sex with men. Three subtypes of gag gene, including CRF01_AE (47.7 %), CRF07_BC (40.9 %) and B (11.4 %) were analyzed by online blast. We designed five small hairpin RNAs (shRNAs) based on the conserved sequences. The gag–EGFP fusion transcript reporter system was used to select the most efficient shRNA. Among the five candidate shRNAs, gag-shRNA-3 represented a broad-spectrum inhibition against all chosen targets. This broad-spectrum shRNA diminished the titer of subtypes B and C of HIV-1 for a hundred orders of magnitude. The gag-shRNA-3 described here is a potential therapeutic agent in the HIV-1 gene therapy.
HIV-1; MSM; gag; shRNA
The rodent barrel cortex has been established as an ideal model for studying the development and plasticity of a neuronal circuit. The barrel cortex consists of barrel and septa columns, which receive various input signals through distinct pathways. The lemniscal pathway transmits whisker-specific signals to homologous barrel columns, and the paralemniscal pathway transmits multi-whisker signals to both barrel and septa columns. The integration of information from both lemniscal and paralemniscal pathways in the barrel cortex is critical for precise object recognition. As the main target of the posterior medial nucleus (POm) in the paralemniscal pathway, layer 5a (L5a) pyramidal neurons are involved in both barrel and septa circuits and are considered an important site of information integration. However, information on L5a neurons is very limited. This study aims to explore the cellular features of L5a neurons and to provide a morphological basis for studying their roles in the development of the paralemniscal pathway and in information integration.
1. We found that the calcium-binding protein calretinin (CR) is dynamically expressed in L5a excitatory pyramidal neurons of the barrel cortex, and L5a neurons form a unique serrated pattern similar to the distributions of their presynaptic POm axon terminals.
2. Infraorbital nerve transection disrupts this unique alignment, indicating that it is input dependent.
3. The formation of the L5a neuronal alignment develops synchronously with barrels, which suggests that the lemniscal and paralemniscal pathways may interact with each other to regulate pattern formation and refinement in the barrel cortex.
4. CR is specifically expressed in the paralemniscal pathway, and CR deletion disrupts the unique L5a neuronal pattern, which indicates that CR may be required for the development of the paralemniscal pathway.
Our results demonstrate that L5a neurons form a unique, input-dependent serrated alignment during the development of cortical barrels and that CR may play an important role in the development of the paralemniscal pathway. Our data provide a morphological basis for studying the role of L5a pyramidal neurons in information integration within the lemniscal and paralemniscal pathways.
Calretinin; L5a pyramidal neuron; Paralemniscal pathway; Posterior medial nucleus; Barrel cortex
In recent years, conjugated polymers have attracted considerable attention from the imaging community as a new class of contrast agent due to their intriguing structural, chemical, and optical properties. Their size and emission wavelength tunability, brightness, photostability, and low toxicity have been demonstrated in a wide range of in vitro sensing and cellular imaging applications, and have just begun to show impact in in vivo settings. In this Perspective, we summarize recent advances in engineering conjugated polymers as imaging contrast agents, their emerging applications in molecular imaging (referred to as in vivo uses in this paper), as well as our perspectives on future research.
Small molecular CCR5 inhibitors represent a new class of drugs for treating HIV-1 infection. The evaluation of the primary resistance mutations associated with entry inhibitors during HIV-1 perinatal transmission is required because they may have a profound impact on the clinical management in MTCT.
To evaluate the primary resistance mutations to maraviroc and vicriviroc during perinatal transmission and analyze the sensitivity of Env derived from mother–infant pairs to maraviroc.
Nine MIPs infected by subtype C HIV-1 were recruited to analyze the prevalence and transmission of primary resistance mutations to maraviroc and vicriviroc. Moreover, Env derived from six MIPs were employed to construct provirus clones and to analyze the sensitivity to maraviroc.
Mutations A316T, conferring partial resistance to maraviroc, T307I and R315Q, both conferring partial resistance to vicriviroc are prevalent in mother and infant cohorts, indicating the transmission of primary resistance mutations during HIV-1 perinatal transmission. However, the mutations of acutely infected mothers seem to directly transmit to their corresponding infants, while some mutations at low frequency of chronically infected mothers would be lost during transmission. Moreover, provirus clones derived from acutely infected MIPs are less susceptible to maraviroc than those from chronically infected MIPs.
Our study suggests that the transmission mode of primary resistance mutations and the sensitivity to maraviroc are dependent on infection status of MIPs either acutely or chronically infected. These results may indicate that higher dose of maraviroc could be needed for treatment of acutely infected MIPs compared to chronically infected MIPs.
MTCT; HIV-1; Subtype C; Primary resistance; Maraviroc; Vicriviroc
Three new rimantadine Schiff bases (RSBs) were prepared, and then the interaction of RSBs with bovine serum albumin (BSA) was investigated using fluorescence, synchronous fluorescence, UV-vis absorption spectroscopy under physiological conditions. The results showed that the three RSBs effectively quenched the intrinsic fluorescence of BSA via static quenching. Binding constant (Ka), number of binding sites (n), and the binding distance (r) between three RSBs and BSA were calculated by Stern-Volmer equation and Förster’s theory in this study. According to the results of displacement experiments of site probes, it was considered that the binding sites were located in hydrophobic cavities in sub-domains IIA of BSA. What is more, synchronous fluorescence studies indicated that the hydrophobicity around tryptophan residues was increased with the addition of rimantadine-o-vanillin (ROV) and rimantadine-4-methoxy-salicylaldehyde (RMS), while there was no apparent change with the addition of rimantadine-salicylaldehyde (RS).
Rimantadine schiff base (RSB); Bovine serum albumin (BSA); Interaction; Fluorescence
The development of early B cells, which are generated from hematopoietic stem cells (HSCs) in a series of well-characterized stages in bone marrow (BM), represents a paradigm for terminal differentiation processes. Akt is primarily regulated by phosphorylation at Thr308 by PDK1 and at Ser473 by mTORC2, and Akt signaling plays a key role in hematopoiesis. However, the role of mTORC2 in the development of early B cells remains poorly understood. In this study, we investigated the functional role of mTORC2 by specifically deleting an integral component, Rictor, in a hematopoietic system. We demonstrated that the deletion of Rictor induced an aberrant increase in the FoxO1 and Rag-1 proteins in BM B cells and that this increase was accompanied by a significant decrease in the abundance of B cells in the peripheral blood (PB) and the spleen, suggesting impaired development of early B cells in adult mouse BM. A BM transplantation assay revealed that the B cell differentiation defect induced by Rictor deletion was not affected by the BM microenvironment, thus indicating a cell-intrinsic mechanism. Furthermore, the knockdown of FoxO1 in Rictor-deleted HSCs and hematopoietic progenitor cells (HPCs) promoted the maturation of B cells in the BM of recipient mice. In addition, we revealed that treatment with rapamycin (an mTORC1 inhibitor) aggravated the deficiency in B cell development in the PB and BM. Taken together, our results provide further evidence that Rictor regulates the development of early B cells in a cell-intrinsic manner by modifying the expression of FoxO1 and Rag-1.
Objective. To evaluate the characteristics and antiangiogenic effects of endostatin-loaded PAMAM on endometriosis in a noninvasive animal model. Materials and Methods. A noninvasive animal model was established by injecting adenovirus-GFP transfected endometrial stromal and glandular epithelial cells subcutaneously into nude mice. Endostatin-loaded PAMAM was prepared and identified by transmission electron microscopy. For in vitro studies, the DNA protection and cytotoxicity of PAMAM were investigated and compared with Lipofectamine 2000. For in vivo study, endostatin-loaded PAMAM was injected into the noninvasive model and evaluated by continuously observing the fluorescent lesion, lesion weight, microvessel density and VEGF immunostaining. Results. Compared with Lipofectamine 2000, PAMAM and HC PAMAM-ES group, MC PAMAM-ES group and LC PAMAM-ES group demonstrated a better stromal cells protective such that MC PAMAM-ES group of CCK8 was 0.617 ± 0.122 at 24 hr and 0.668 ± 0.143 at 48 hr and LC PAMAM-ES group of CCK8 was 0.499 ± 0.103 at 24 hr and 0.610 ± 0.080 at 48 hr in stromal cells (P < 0.05) but similar cytotoxicity in glandular epithelial cells in vitro. After 16 hrs of digestion, DNA decreased slightly under the protection of PAMAM. Endostatin-loaded PAMAM of HD PAMAM-ES group and LD PAMAM-ES group inhibited the growth of the endometriotic lesion in vivo at days 15, 20, 25 and 30 detected by noninvasive observation after injecting one dose endostatin of various medicines into the endometrial lesion in each mouse on day 10 (P < 0.05) and confirmed by lesion weight at day 30 with HD PAMAM-ES group being 0.0104 ± 0.0077 g and LD PAMAM-ES group being 0.0140 ± 0.0097 g (P < 0.05). Immunohistochemistry results showed that endostatin-loaded PAMAM reduced the microvessel density 3.8 ± 2.4 especially in HD PAMAM-ES group in the lesion (P < 0.05). Conclusion. Endostatin-loaded PAMAM inhibits the development of endometriosis through an antiangiogenic mechanism and can be observed through the noninvasive endometriosis model.
Heavy ion beams with high linear energy transfer exhibit more beneficial physical and biological performance than conventional X-rays, thus improving the potential of this type of radiotherapy in the treatment of cancer. However, these two radiotherapy modalities both cause inevitable brain injury. The objective of this study was to evaluate the effects of heavy ion and X-ray irradiation on the cytoskeleton and cytomechanical properties of rat cortical neurons, as well as to determine the potential mechanism of neuronal injury after irradiation. Cortical neurons from 30 new-born mice were irradiated with heavy ion beams at a single dose of 2 Gy and X-rays at a single dose of 4 Gy; subsequent evaluation of their effects were carried out at 24 hours after irradiation. An immunofluorescence assay showed that after irradiation with both the heavy ion beam and X-rays, the number of primary neurons was significantly decreased, and there was evidence of apoptosis. Radiation-induced neuronal injury was more apparent after X-irradiation. Under atomic force microscopy, the neuronal membrane appeared rough and neuronal rigidity had increased. These cell changes were more apparent following exposure to X-rays. Our findings indicated that damage caused by heavy ion and X-ray irradiation resulted in the structural distortion and rearrangement of the cytoskeleton, and affected the cytomechanical properties of the cortical neurons. Moreover, this radiation injury to normal neurons was much severer after irradiation with X-rays than after heavy ion beam irradiation.
nerve regeneration; radiation brain injury; neurons; heavy ion; X-ray; cytoskeleton; cytomechanical properties; atomic force microscopy; neural regeneration
Human immunodeficiency virus type 1 (HIV-1) Vif requires core binding factor β (CBF-β) to degrade the host APOBEC3 restriction factors. Although a minimum domain and certain amino acids of HIV-1 Vif, including hydrophobic residues at the N-terminal, have been identified as critical sites for binding with CBF-β, other regions that potentially mediate this interaction need to be further investigated. Here, we mapped two new regions of HIV-1 Vif that are required for interaction with CBF-β by generating a series of single-site or multiple-site Vif mutants and testing their effect on the suppression of APOBEC3G (A3G) and APOBEC3F (A3F). A number of the mutants, including G84A/SIEW86-89AAAA (84/86–89), E88A/W89A (88/89), G84A, W89A, L106S and I107S in the 84GxSIEW89 and L102ADQLI107 regions, affected Vif function by disrupting CBF-β binding. These Vif mutants also had altered interactions with CUL5, since CBF-β is known to facilitate the binding of Vif to CUL5. We further showed that this effect was not due to misfolding or conformational changes in Vif, as the mutants still maintained their interactions with other factors such as ElonginB, A3G and A3F. Notably, G84D and D104A had stronger effects on the Vif-CUL5 interaction than on the Vif-CBF-β interaction, indicating that they mainly influenced the CUL5 interaction and implying that the interaction of Vif with CUL5 contributes to the binding of Vif to CBF-β. These new binding interfaces with CBF-β in HIV-1 Vif provide novel targets for the development of HIV-1 inhibitors.
Significant efforts have been paid to exploring the fundamental properties of topological insulators (TIs) in recent years. However, the investigation of TIs as functional materials for practical device applications is still quite limited. In this work, electronic sensors based on Bi2Te3 nanoplates were fabricated and the sensing performance was investigated. On exposure to different surrounding environments, significant changes in the conducting properties were observed by direct electrical measurements. These results suggest that nanostructured TIs hold great potential for sensing applications.